Canadian Patent Application 2,166,265 by Quinn Holtby describes a method and apparatus of preventing fluid leakage from that portion of a completed oilwell known as a "Christmas Trees". The Holtby patent discloses an annular ring which is incorporated as part of the Christmas Tree. Around the annular ring is positioned a catch pan with a drainage opening connected by conduit to a storage container.
While the Holtby reference is a useful apparatus, installation requires disassembly and reassembly of the Christmas Tree.